The study examined the biological behavior of the fish, Harpagifer antarcticus, when exposed to fresh water and thaws. Although it has no commercial impact, it is of great ecological importance.

Example of a spiny fish in Antarctica.

Florencia Hidalgo, La Tercera. As global warming increases from year to year, raising global temperatures, living beings seek ways to adapt quickly.

To examine how some species are adapting, Luis Vargas-Chacoff and Kurt Paschke, both researchers from the Universidad Austral de Chile, studied the Antarctic fish, Harpagifer antarcticus (locally known as espinudo) that, today, is exposed to a greater amount of fresh water coming from glacial melting.

The researchers took 25 of these fish and exposed them, in groups of five, to different levels of salinity in the water. Melting glaciers produce fresh water, but the fish require a certain level of salinity to live.

“Of the five fish that we exposed to the lowest salinity level, one died; that is 20%, which is not minor. If the experiment had lasted longer, all the fish would have died, even those exposed to higher levels of salinity,” says Vargas-Chacoff, also a scientist at the Research Center Dynamics of High Latitude Marine Ecosystems (IDEAL) of the Universidad Austral de Chile.

Fish release excess salt through a process involving the gills, kidneys, and intestinal walls. If fresh water increases, changing the salinity of the environment in which these fish live, they must stop releasing salt and, instead, retain it in order to survive. However, Harpagifer antarcticus cannot perform this process.

Vargas-Chacoff warns that the thaw is threatening. “The only option that this fish has for survival in the event of an excess of fresh water is to migrate and go to deeper waters. But if it goes deeper… the rocks are not where it finds food,” he says.

Although Harpagifer antarcticus does not have a significant commercial impact, it does have ecological importance as part of the penguin feeding chain. “In millions of years, it has never faced a change like that occurring in the last 50. The animal is not able to adapt to the environment. To adjust, its diet will have to change, as will that of the penguin.”

Other species that are in danger are amphipods, small crustaceans that are very abundant and important. Vargas-Chacoff says that experiments done this year showed that these crustaceans suffer greatly in fresh water and are also unable to adjust to low salinity levels.